As mentioned above, there is a limit to the number of parameters.
Perhaps you are calling the C/C++ function from your VBA code as a
means of creating a worksheet function out of a C/C++ DLL. The fastest
way to do this is through an XLL add-in. These use the Excel C API to
register user defined functions.

RapidXLL_NET automatically builds XLL add-ins ( as well as .NET
libraries ) from native C / C++ headers. Download a free trial at
http://www.RapidXLL.net The tool also allows a bit of customization.
You can default parameters and hide the them from worksheet users so
that the 21 parameter functions comes down to just 5 parameters. You
can also re-name the function in the process.

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The RapidXLL Team
http://www.RapidXLL.net




T
Lynn McGuire wrote:
I am extending a DLL that we have written for Excel VBA to call.

One of the new functions has 21 arguments. However, Excel
refuses to compile the VBA code and says that it cannot find
the function. Is there a limit on the number of arguments for
DLL functions in Excel VBA ?

Thanks,
Lynn McGuire